Description
The Trane CNT03520 SPDT Pressure Switch 0.15″ WC is an air-pressure-sensing safety part used in HVAC systems. It is to monitor draft or airflow conditions within the combustion system and actuates electrical contacts based on a set pressure threshold of approximately. Typically installed near the inducer assembly and connected via tubing, it verifies proper venting before allowing ignition. Within the system, the switch operator is part of the safety control circuit, ensuring adequate airflow and preventing operation under unsafe conditions such as blocked vents or insufficient.









